The Madison Police Department said Kelly was arrested after the department received information on Thursday about the "possible exploitation of a vulnerable adult resident" at the nursing home.

The resulting investigation determined that the 28-year-old Kelly had "illegally and improperly obtained an image of a vulnerable adult resident without their consent for his own benefit." Kelly is currently being held on $100,000 bond.

Kelly maintains a blog, "Constitutional Clayton," where he posted the video, which The Clarion-Ledger reported as being "anti-Cochran" and favorable to Chris McDaniel, Cochran's intra-party challenger.

The video has reportedly been taken down. The newspaper also reported that Rose Cochran has been living in St. Catherine's Village facility since 2000. She suffers from progressive dementia.

Don Clark, an attorney who represents the Cochrans, told Business Insider in a statement the picture was "taken inside of Mrs. Cochran’s room near her bedside."

"We believed a crime may have been committed and we immediately notified the City of Madison Police Department," Clark said.

"The police conducted an investigation, still in progress, resulting in the arrest last night. As you can imagine, Senator Cochran’s first concern was that of the safety of his wife as well as the invasion of her privacy and dignity."

The arrest comes only a few weeks before the Republican primary in what has been one of the most intense GOP establishment vs. grassroots fights of the 2014 campaign.

McDaniel moved quickly to distance himself from Kelly, who posted a number of favorable items toward McDaniel, including one that asked whether he might be "the next Rand Paul."

"I've reached out to Senator Cochran directly to express my abhorrence for the reprehensible actions of this individual. This criminal act is deeply offensive and my team and I categorically reject such appalling behavior," McDaniel said in a statement released by his campaign.

"My thoughts and prayers are with Senator Cochran and his family. Politics is about the exchange of ideas and this type of action has no place in politics whatsoever and will not be tolerated."